In the game, you control a little bird called Kururin in his stick-shaped helicopter, appropriately named "Helirin", in a quest to save your siblings.
The gameplay consists of maneuvering the ever-rotating Helirin through many narrow passages, moving obstacles and stationary turrets. In the story mode, you need to steer your Helirin through 10 stages (with names like Cake Land, Star Land and Cloud Land), each with three levels that you need to finish in a linear fashion. Then there's the Challenge Mode, which has 50 very short challenge levels that are appropriately very difficult.
The game also has two sequels that appeared only in Japan: Kururin Paradise (GBA) and Kururin Squash! (GameCube).
Even though the series was generally exclusive to Japan, the first game came out in Europe and was also released on the Wii U Virtual Console and the Nintendo Switch Online Expansion Pass in North America in February 2016 and 2023 respectively. In addition the Helirin appeared as an Assist trophy in Super Smash Bros. Brawl.
Kuru Kuru Kururin provides examples of:
- Anti-Frustration Features: You can always cheat a difficult level outside of Easy Mode by resizing the Helirin at the entry point, but the game will refuse to record your time upon reaching the goal.
- Big Boo's Haunt: The levels in World 9 (Ghost Castle), as its name hints, take place inside a haunted castle filled with ghosts, sarcophages, chalices with creepily-colored flames, and fountains of lava in the background. Since this is the final world, the levels require mastery in regards of controlling Kururin's ship, and avoiding once again all the types of hazards and tricky layouts that appeared in the previous worlds.
- Brutal Bonus Level: If you finish every single one of the 50 challenge level without getting hit (which is quite difficult), you unlock 5 more challenge levels, each of them very difficult.
- Denser and Wackier: The sequels are noticably more comical and silly with an updated art style to boot.
- Difficulty Levels: There's an "Easy" and a "Normal" mode. In Easy mode, the Helirin is half the size, making every level so much easier.
- Eternal Engine: The levels in Machine Land take place within a dangerous factory, and each one introduces a type of hazard that has top be avoided. The first level has metallic crushers that move sideways, the second level has cubic boxes between which spiked metallic spheres roll to be transported, and the third as both those and cannons that shoot balls of dark energy at Kururin's ship (and those cannons always aim at him).
- Excuse Plot: Yes, you see your siblings in level 3 of each stage, but all you do is pick them up, get to the end of the level and that's it but Kururin Squash would give an actual reason for this.
- Foul Waterfowl: Professor Isogashima, the duck billed Mad Scientist and Big Bad of Kururin Squash who kidnaps Kururin's siblings and controls all of the bosses in the game. However being a game as lighthearted as it is he's not much of a threat.
- Green Hill Zone: The levels in World 1 (Grasslands) take place within lush, green prairies where some houses and hanging clothes can be seen. The levels' layouts are very beginner-friendly.
- Inexplicably Tailless: None of the animal characters in this series have tails, but Kururin Squash gave the tituliar bird a single curled black feather.
- Jungle Japes: The levels in World 3 (Jungle) are placed above a very dense palmtree biome with some huts built among the flora, and inhabited by masked people with spears and animals like chimpanzees, snakes and gorillas. The levels have small cul-de-sacs and dead ends so Kururin can time his travel across the narrow paths while his ship continues rotating.
- Level Ate: The levels in World 4 (Cake Land) take place within a mountain made of cake, and the background also features assorted things like cookiemen, birthday candles, jewels shaped and colored like strawberries, houses shaped like cake slices or apples, and gelatine. The paths and corners are unusually narrow and are positioned diagonally, and require Kururin to go through them with good timing and pulse.
- Level in the Clouds: The levels in World 6 (Cloud Land) are placed very high in the skies, and several hot-air balloons and zeppelins can be seen in the background. The levels have unusual wall layouts, being shaped like four-point stars, circles or elongated hexagons.
- No Antagonist: The GBA games do not have villains to speak of and the closest they get is Kururin Paradise having a group of magicians who challenge the player to minigames.
- Palmtree Panic: The levels in World 2 (Ocean) go through a beautiful, pristine ocean in which marine animals like sea turtles, fish and crabs can be seen. The levels' paths have a curvier layout compared to those of the first world, but aren't particularly challenging; however, they do introduce the wall springs, which invert the rotating orientation of Kururin's ship, which comes in handy to traverse curves or corner that are impossible to go through if the ship isn't rotating with the right orientation.
- Primary-Color Champion: Kururin is the series protagonist and has blue feathers, a yellow beak and legs, and a red scarf and goggles respectively.
- Slippy-Slidey Ice World: The levels in World 8 (Ice Land) go through an arctic-styled landscape inhabited by polar beans, reindeer and Polar Penguins, and there are also snowmen, igloos and Christmas trees in the background. The levels have a maze-like design, and the paths are usually placed next to each other in a ringed pattern.
- Space Zone: The levels in World 7 (Star Land) take place in outer space, showcasing rockets, UFOs and planets of varying colors and sizes in the background. The levels feature walls shaped like octagons, small dots or diamonds that are placed very close to each other, thus requiring Kururin to move around very carefully. The third levels also has mazes and corridors with lots of springs, which mess up with the orientation of Kururin's ship.
- Speaking Simlish: Voices in Kururin Squash! during cutscenes are done with a high pitched gibberish sound similiar to what Splatoon would have.
- Underground Level: The levels in World 5 (Cave) take place inside a rocky mountain with bonfires and dinosaur fossils in the background. One of the game's supporting characters advise Kururin to move across the paths quickly, due to them being too narrow to be traversed slowly without making the ship clash against the walls. The second level adds elements that become more common in later levels, such as compactors, spiked metallic spheres and a spring maze (and the third level leans closer to being a Lethal Lava Land, due to the boiling red ground and the obsidian formations in the background).